You would have to either make things up or again draw meaning from nothing. Even if she were secretly poly this entire time with hidden messages about her that apparently a small percentage of people can see, it would still be deceptive and silly on the writer's part in the first place. Neither of these scenarios are good at all. The only time the game explicitly suggests that she's poly is... Halsin, which still remains inconsistent with what majority of people doing her romance will see, and nothing is ever going to change that.
